JP7130247B2 - Probes and measuring devices for solar cells - Google Patents

Description

The present invention relates to a probe used for measuring the output of a solar cell and a measuring device for a solar cell using the probe.

The quality check and classification of solar cells are performed based on the measurement results of the current and voltage characteristics generated when the solar cells are irradiated with light from a solar simulator.

For example, in the case of a busbar-less solar cell, a bar-shaped probe is arranged at the position where the conventional busbar electrode was, and is brought into contact with a plurality of finger electrodes to measure the output from the solar cell.

By the way, the finger electrodes formed on the surface of the solar cell by screen printing have minute variations in height. For this reason, in the conventional probe, the contact state of each finger electrode becomes unstable, and the electrical resistance greatly changes each time measurement is performed, resulting in a problem of reproducibility of measurement.

In order to solve such a problem, the present applicant has developed a general comb-teeth structure having a large number of linear contacts formed of thin metal wires and spring elements for elastically supporting each contact. proposed a bar-shaped probe (see Patent Document 1).

Japanese Patent Application No. 2018-234001

The inventors of the present application conducted extensive studies on the above-described bar-type probe, and found that by reducing the change in the posture of each contact, the reproducibility and durability of the output measurement of the solar cell can be further improved. I discovered that for the first time.

The present invention has been made based on the above findings, and aims to further improve the reproducibility and durability of the output measurement of a solar cell.

That is, the probe according to the present invention is a probe used for measuring the electrical characteristics of a solar cell, comprising a plurality of thin plate bodies stacked in the thickness direction, and the plurality of thin plate bodies sandwiched from the outside in the thickness direction. and a pair of covers, wherein the thin plate body is a long thin plate-like main body and a thin plate having a predetermined width in the longitudinal direction of the main body, and the width direction is aligned along the longitudinal direction of the main body. and a spring element formed of a fine wire connecting between the main body and the plurality of contacts, wherein the pair of covers cover the contacts with a thickness. It is characterized by comprising a pair of tilting regulating portions that sandwich the contact in a direction and regulate tilting of the contact.

With such a structure, each contact can be very softly supported by the spring element, and the probe can be pressed against the solar cell even if there is a difference in height between the finger electrodes of the solar cell. The difference can be absorbed by the elasticity of the spring element.

Furthermore, since the tilting of each contactor is regulated by the pair of tilting regulating portions, the attitudes of the contactors can be substantially aligned when the probe is pressed against the solar battery cell. For this reason, it becomes difficult for each contactor to cause a change in contact state due to a difference in posture.

For these reasons, it is possible to further improve the reproducibility in the measurement of the output characteristics of the photovoltaic cell compared to the conventional art. In addition, since the contactor is less likely to undergo a large change in posture or deformation, the durability of the probe can be improved.

In order to restrict the tilting of the contactor within a predetermined range and to allow the contactor to move freely in the pressing direction in order to absorb unevenness of the finger electrodes by the spring element, the pair of tilting restricting portions are provided. , a pair of parallel plates, and a gap is formed between the inner surfaces of the plates and the face plate portion of the contactor.

In order to form a minute gap between the pair of parallel plates and the face plate portion of the contactor and to keep the gap constant, the pair of tilt regulating portions are provided between the pair of parallel plates. What is necessary is just to provide the spacer structure which interposes and maintains the space|interval of said pair of parallel plates to a predetermined value.

As a specific embodiment of the spacer structure, it is a pair of protrusions protruding from a pair of parallel plates toward the surfaces facing each other, and the pair of protrusions are in contact with each other to form the pair of parallel plates. is configured such that the distance between them is maintained at a predetermined value.

To allow the pair of protrusions to come into contact with each other without causing interference between the protrusions and the contacts while a large number of the contacts are densely arranged in the longitudinal direction of the main body. A hole through which the projection is inserted or a notch for bypassing the projection may be formed in at least a part of the plurality of contacts.

In order to allow the spring element to be greatly deformed and the contactor to be supported very softly even with the cover provided, the spring element should protrude outside the main body portion. It is sufficient that the pair of covers is curved with respect to the thickness direction of the thin plate body, and that the pair of covers further includes an opening that exposes at least part of the spring element.

In order for the probe according to the present invention to make it easier for any of the contactors to contact each finger electrode of the solar cell, the plurality of contactors are provided at predetermined intervals along the longitudinal direction of the main body. It is sufficient that the plurality of contactors provided in at least two thin plate bodies are provided at different intervals.

For example, in three continuous finger electrodes, one contact bridges two finger electrodes at both ends, and the contact does not contact the middle finger electrode. It is sufficient that the length dimension in the arrangement direction of the child is set to be smaller than twice the installation interval of each finger electrode.

As a specific example of the interval at which the plurality of contacts are arranged, the predetermined interval may be set such that the plurality of contacts are in contact with one or two finger electrodes.

For example, in order to use a probe suitable for measuring the IV characteristics of a solar cell by a four-probe method or the like, at least one of the plurality of thin plate bodies stacked in the thickness direction is used for voltage measurement. and the other thin plate is a thin plate for current measurement, further comprising an insulating layer formed between the thin plate for voltage measurement and the thin plate for current measurement. Anything is fine.

A solar cell measuring device comprising a probe according to the present invention and a current-voltage measuring mechanism connected to the probe can improve reproducibility in output measurement of a solar cell and durability as a device conventionally. can be improved.

As described above, according to the probe according to the present invention, since the fall-regulating portion is formed by the cover sandwiched from the outside of the thin plate body having the contactor, the contactor is prevented from being pressed against the solar cell when the probe is pressed against the solar cell. You can prevent it from falling down and changing its posture. As a result, since the postures of the plurality of contacts can be kept substantially constant in each measurement, the reproducibility in the output measurement of the photovoltaic cell and the durability as a probe can be improved more than ever.

BRIEF DESCRIPTION OF THE DRAWINGS The schematic diagram which shows the probe which concerns on one Embodiment of this invention, and the measuring apparatus for photovoltaic cells. The schematic diagram which shows arrangement|positioning of the probe with respect to the photovoltaic cell in the same embodiment. The schematic perspective view of the probe in the same embodiment. A schematic plan view enlarging a part of each thin plate in the same embodiment. FIG. 4 is a longitudinal sectional view of the probe in the same embodiment;

A probe 3 according to an embodiment of the present invention and a photovoltaic cell measurement device 100 using the same will be described with reference to FIGS. 1 to 5. FIG. The photovoltaic cell measurement apparatus 100 of the present embodiment is for measuring the IV characteristics of the photovoltaic cells SC. It is used for In this embodiment, the IV characteristics of a high-efficiency solar cell such as a heterojunction solar cell are measured as the solar cell SC.

Next, an outline of each part constituting the photovoltaic cell measurement device 100 will be described. As shown in FIG. , an irradiation control unit 13 that controls the solar simulator 1, a sample table 2 on which the solar cell SC is placed, a probe 3 that contacts the finger electrodes F formed on the surface of the solar cell SC, and a solar cell It is provided with at least an IV tester 5 for measuring the SC IV characteristics and a control arithmetic unit 6 (personal computer) for controlling each section and performing various calculations.

The solar simulator 1 is composed of a substantially rectangular parallelepiped housing 11 with an open bottom and a light source 12 housed inside the housing 11 on the upper surface side. The light source 12 is, for example, a long-arc xenon lamp formed in a substantially ring shape, and irradiates the solar cell SC with simulated sunlight as flash light (pulse light).

The irradiation control unit 13 controls the irradiation state of the simulated sunlight that the solar simulator 1 irradiates onto the solar cells SC.

The sample stage 2 is connected to a vacuum pump 22 so that the back surface of the solar cell SC can be held by suction, and the temperature of the solar cell SC is set at a temperature recommended as a measurement condition when measuring the IV output. It is cooled by a chiller 21 to keep it constant.

The IV tester 5 is electrically connected to the photovoltaic cell SC when the photovoltaic cell SC is placed on the sample stage 2, and serves as a load for sweeping the voltage applied to the photovoltaic cell SC. a power source, an applied voltage control section for controlling the voltage applied to the solar cell SC by the load power source, and the solar cell while the applied voltage is being swept to the solar cell SC by the load power source. At least a current-voltage measuring mechanism including an ammeter and a voltmeter for measuring the current and voltage output from the SC via the probe 3 is provided. Based on the current and voltage measured by the IV tester 5, the control arithmetic device 6 calculates the IV characteristics of the solar cell SC, the maximum output Pmax, the short-circuit current Isc, the open-circuit voltage Voc, and the like.

Next, details of the bar-type probe 3 will be described.

The probe 3 is fixed to a driving mechanism (not shown) and driven vertically so as to come into contact with and separate from the solar cell SC placed on the sample stage 2 . The probe 3 is connected to the ammeter and voltmeter in the IV tester 5 via cables.

In the first embodiment, as shown in FIG. 2, a total of five probes 3 are arranged in parallel so as to be perpendicular to each finger electrode F for one solar cell SC. That is, the solar cell SC is a busbarless solar cell, and a plurality of finger electrodes F for collecting current output from each point on the substrate are screen-printed in parallel with silver paste or the like. In other words, each finger electrode F is provided at predetermined intervals, and the longitudinal direction of the probe 3 of this embodiment is arranged along the direction in which each finger electrode F is arranged. The probes 3 are arranged so as to be in contact with each finger electrode F at the same time. Here, the place where the probe 3 is arranged is also the place where wire electrodes and the like are formed when a solar panel is formed from a plurality of solar cells SC in a post-process.

The heights of the finger electrodes F formed by screen printing vary due to fine irregularities such as reflection structures formed on the surface of the substrate and printing accuracy problems. Specifically, when one finger electrode F is viewed along the extending direction, not only does the height change, but also the height at the point where the probe 3 is arranged in each finger electrode F is minute. are different.

Therefore, if the probe is rigid and cannot absorb the difference in height between the finger electrodes F, the probe 3 is supported only by the finger electrodes F which are formed higher than the other finger electrodes with respect to the substrate surface. There is a possibility that all the finger electrodes F cannot be contacted. If the IV characteristic is measured while some of the finger electrodes F are not in contact with the probe 3, the current or voltage will be underestimated and correct measurement will not be possible.

For this reason, the probe 3 of this embodiment absorbs the difference in height so as to achieve good contact with all the finger electrodes F even if there is a difference in height at the contact point with each finger electrode F. is configured to

Specifically, as shown in FIGS. 3 to 5, the probe 3 is composed of two thin plate bodies 3A made of a conductor that are laminated together in the thickness direction, and the laminated thin plate bodies 3A are laminated in the thickness direction. It is formed by sandwiching it with a pair of covers 3B from the outside.

As shown in FIGS. 3 and 4, the thin plate member 3A has a long thin plate-like main body portion 31 and a predetermined width with respect to the longitudinal direction of the main body portion 31, and is aligned along the longitudinal direction of the main body portion 31. and a spring element 33 formed of a fine wire connecting between the body portion 31 and the contact 32 .

Here, the thin plate member 3A is formed by punching and bending a thin plate made of, for example, a copper alloy to form the spring element 33 formed of a thin wire. Here, the thickness of the thin plate member 3A is, for example, 1 mm or less, and the diameter of the spring element 33 is also 1 mm or less.

The body portion 31 has a substantially elongated rectangular plate shape, and both ends thereof are held by a drive mechanism (not shown). Further, the body portion 31 transmits current or voltage from the solar cell SC via the contactor 32 and the spring element 33 to the ammeter or voltmeter. The body portion 31 of each thin plate member 3A is adhered and integrated. In this embodiment, one thin plate 3A is for current measurement, and the other thin plate 3A is for voltage measurement. The thin plate member 3A for voltage measurement and the thin plate member 3A for current measurement are bonded with an adhesive while an insulating layer is formed by insulating paper, for example. That is, one probe 3 of this embodiment is designed to be able to perform both current measurement and voltage measurement.

As shown in FIGS. 4 and 5, the contacts 32 are rectangular thin plate portions having a predetermined width in the longitudinal direction of the main body 31 in this embodiment, and are periodically arranged at predetermined intervals. . Here, the contactor 32 is formed in a rectangular shape whose longitudinal direction is the contact/separation direction with respect to the solar cell SC, and whose lateral direction is the longitudinal direction of the main body portion 31 . The width dimension, which is the longitudinal dimension of each contactor 32 in the lateral direction, is set to be smaller than twice the spacing between the finger electrodes F. As shown in FIG. For example, the width dimension of the contactor 32 and the installation interval are configured so that one or two finger electrodes F can come into contact with the contactor 32 . In this embodiment, as shown in FIG. 5, the body portion 31 and the contactor 32 of the contactor 32 are arranged substantially on the same plane in the natural state. A part of the contactor 32 is formed with a hole through which a protrusion 38 (to be described later) is inserted, or a notch for bypassing the protrusion 38 . As shown in FIG. 4, the intervals between the contacts 32 on the two thin plates 3A are the same, but the intervals are shifted by half a interval.

The spring elements 33 are thin wires that connect between the body portion 31 and the plurality of contacts 32, respectively, as shown in FIGS. The spring element 33 is formed to connect both ends of one contact 32 to the body portion 31 separately. In other words, each contactor 32 is elastically supported independently, and individual displacement occurs in each contactor 32 . Each spring element 33 has the same shape, and has a substantially sinusoidal shape that curves in the thickness direction of the thin plate member 3A. Although the amplitude of each spring element 33 is substantially constant in this embodiment, the amplitude may be varied depending on the location. In addition, the spring elements 33 of the two thin plate members 3A are symmetrical in orientation, and in the stacked state, the space between the adjacent spring elements 33 of one thin plate member 3A corresponds to that of the other. Spring element 33 of sheet 3A is inserted. Further, as shown in FIG. 5, the contactors 32 of the respective thin plate members 3A are configured to be pushed inward by the elastic restoring force of the spring elements 33. As shown in FIG.

As shown in FIGS. 3 and 5, the cover 3B has a fixing portion 34 attached and fixed to the main body portion 31, and an opening for exposing at least part of the spring element 33 to the outside of the cover 3B. 35, and a fall regulating portion 36 that sandwiches the contactor 32 of the stacked thin plate bodies 3A from the outside in the thickness direction and regulates the fall of the contactor 32.例文帳に追加

The fixing portion 34 is a substantially elongated rectangular plate-like portion, and is fixed to the thin plate member 3A in an insulated state. In this embodiment, since the fixed portion 34 is insulated from the thin plate 3A, a terminal for measuring current or voltage is connected to the thin plate 3A. 3A may be fixed in a conducting state, and the current or voltage of the solar cell SC may be measured via the fixing portion 34 or a conductor provided on the fixing portion 34 .

The opening 35 is a substantially rectangular portion that opens in the central portion of the cover 3B, and exposes the outwardly bulging portions of the spring element 33 to the outside of the cover 3B. That is, since the opening 35 is formed, the spring element 33 is not hindered even if the spring element 33 is deformed.

As shown in FIG. 5, the fall-regulating portion 36 is a pair of parallel plates 37 that sandwich the contactor 32 provided on the lower side of the opening 35 in the thickness direction, and keeps the distance between the parallel plates 37 constant. and a spacer structure.

As shown in the cross-sectional view of FIG. 5, the pair of parallel plates 37 are configured to sandwich the contactor 32 with a minute gap between them and the face plate portion of the contactor 32 . That is, even if the contactor 32 is displaced in the contacting/separating direction of the probe 3 to the solar cell SC, the face plate portion thereof does not come into contact with the parallel plate 37, and the movement is not hindered. In addition, since only a small gap exists between the parallel plate 37 and the face plate portion of the contactor 32, the contactor 32 is restricted within a very limited range of posture change during displacement. Therefore, the contactor 32 can be substantially displaced only in the contact/separation direction of the probe 3 . The gap between the parallel plate 37 and the contactor 32 is set to a predetermined value based on the permissible amount of change in posture of the contactor 32 .

The spacer structure consists of a pair of protrusions 38 protruding from the inner side surfaces of the pair of parallel plates 37 toward the surfaces facing each other. When the cover 3B is attached to the thin plate member 3A, the protrusions 38 come into contact with each other to prevent the parallel plates 37 from coming closer to each other. The gap between is kept at a predetermined value. In this embodiment, the projections 38 are arranged at predetermined intervals in the longitudinal direction of the main body 31 , and the intervals are kept substantially constant regardless of the location of the parallel plate 37 .

According to the probe 3 of the present embodiment configured in this way, the parallel plate 37 sandwiched by the cover 3B covering about half of the contactor 32 from the base end side constitutes the fall-regulating portion 36. is pressed against the solar cell SC, the contactor 32 can be caused to be displaced only in the contact/separation direction without almost causing the contactor 32 to fall.

Therefore, it is possible to prevent a situation in which the contact state of each contactor 32 with respect to the finger electrode is changed due to a change in attitude due to the tilting, and the reproducibility of measurement is lowered. Further, as shown in the cross-sectional view of FIG. 5, in this embodiment, the main body portion 31 of the thin plate member 3A and the contactor 32 are on the same plane and are arranged so as to be aligned in a straight line with respect to the contact/separation direction. Therefore, even when the probe 3 is pressed against the solar cell 3A, force is applied straight to the contactor 32, and moment is less likely to occur. This also makes it difficult for the contactor 32 to change its posture.

Other embodiments will be described.

In the above-described embodiment, the spring element is a fine wire formed in a sinusoidal shape that curves in the thickness direction, but the present invention is not limited to such. For example, when the spring element is formed in a sinusoidal shape, the number of waves is not limited to that shown in the above embodiment, and the spring element may be formed in an approximately S-shape. Also, the amplitude may vary at each portion of the spring element. Furthermore, the spring element may be formed only in the plane containing the body and the contact, and the deformation also occurs in this plane. Specifically, the spring element may be a generally rectangular thin wire that is elastically deformable in a plane.

If the spring element has the form described above, the cover need not have an opening.

The number of laminated thin plates is not limited to two, and may be three or more. Further, the protrusions forming the spacer structure are not limited to those shown in the above embodiments. For example, a convex portion may be formed only on one side so as to reach from one parallel plate to the face plate portion of the other parallel plate.

In addition, as long as it does not contradict the gist of the present invention, various modifications of the embodiments and parts of the embodiments may be combined.

DESCRIPTION OF SYMBOLS 100... Photovoltaic cell measuring apparatus 3... Probe 3A... Thin plate body 31... Body part 32... Contactor 33... Spring element 3B... Cover 34... Fixing part 35... Opening 36... Collapse regulating part 37... Parallel plate 38... Convex part

Claims (11)

A probe used to measure the electrical characteristics of the solar cell by contacting and separating from the solar cell,
a plurality of thin plate bodies laminated in the thickness direction;
a pair of covers that sandwich the plurality of thin plate bodies from the outside in the thickness direction,
The thin plate body
a long thin plate-like main body;
A plurality of thin plates having a predetermined width in the longitudinal direction of the main body and extending in a direction toward and away from the solar cell, and arranged side by side so that their width directions are aligned along the longitudinal direction of the main body. a contact;
a spring element formed of a fine wire connecting between the main body and the plurality of contacts,
the pair of covers,
A probe comprising a pair of flat surfaces sandwiching the plurality of thin plate contacts in a thickness direction. The pair of planes are inner planes of a pair of parallel plates arranged to sandwich the contactor, which is a thin plate, in the thickness direction, and the inner planes of the pair of parallel plates and the contact, which is a thin plate 2. The probe according to claim 1, wherein the planes of the child face plate portions are opposed to each other, and a gap is formed between each inner plane of the pair of parallel plates and the face plate portion and each plane. A spacer structure is interposed between the pair of parallel plates to keep the distance between the pair of parallel plates at a predetermined value, and the spacer structure is provided between the two contacts arranged side by side along the longitudinal direction. 3. The probe of claim 2 formed between. The spacer structure is a pair of protrusions protruding from a pair of parallel plates toward surfaces facing each other, and the pair of protrusions are in contact with each other to maintain the distance between the pair of parallel plates at a predetermined value. 4. The probe of claim 3, configured to hang. 5. The probe according to claim 4, wherein a hole through which said projection is inserted or a notch for bypassing said projection is formed in at least part of said plurality of contacts. the spring element is curved with respect to the thickness direction of the thin plate body so as to protrude outward from the main body;
the pair of covers,
2. The probe of claim 1, further comprising an opening exposing at least a portion of said spring element. The plurality of contacts are provided at predetermined intervals along the longitudinal direction of the main body,
2. The probe according to claim 1, wherein the plurality of contactors provided in at least two thin plate bodies are provided at different intervals. 8. The probe according to claim 7, wherein the length dimension in the arrangement direction of the plurality of contactors is set to be smaller than twice the spacing between the finger electrodes. 8. The probe according to claim 7, wherein said predetermined interval is set so that a plurality of said contactors are in contact with one or two finger electrodes. At least one of the plurality of thin plate bodies stacked in the thickness direction is a thin plate body for voltage measurement, and the other thin plate bodies are thin plate bodies for current measurement,
2. The probe according to claim 1, further comprising an insulating layer formed between said thin plate for voltage measurement and said thin plate for current measurement. a probe according to claim 1;
and a current-voltage measuring mechanism connected to the probe.

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